Rapid Growth of Salmonella Enteritidis in Egg White Reconstituted from Industrial Egg White Powder

The aim of this study was to evaluate the consequences of the egg white-drying process on egg white ability to limit Salmonella Enteritidis growth in addition to the elucidation of the factors involved. We observed rapid growth of Salmonella Enteritidis inoculated in egg white reconstituted from industrial powder in comparison with that observed in liquid egg white collected in the laboratory: Salmonella cell counts rose from 103 to 108 cells/ml of egg white from powder during 24 h incubation at 30°C. This rapid growth was observed in powder from all egg-breaking factories investigated, and it was comparable to that observed in optimum medium (tryptone soy broth). In view of the mechanism of egg white resistance and the major role played by iron availability and by ovotransferrin, we investigated several hypotheses to explain this rapid growth: iron provided during the drying process and/or denaturation of protein (especially ovotransferrin). The rapid growth observed in egg white reconstituted from powder was in relation to egg white protein denaturation and especially ovotransferrin denaturation during powder pasteurization that enhanced the availability of iron necessary for Salmonella growth. The major role played by ovotransferrin and iron deficiency on Salmonella growth in egg white was illustrated in this study.

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Factors Involved in the Inhibition of Growth of Salmonella enteritidis in Liquid Egg White

Journal of Food Protection ◽

10.4315/0362-028x-60.11.1318 ◽

1997 ◽

Vol 60 (11) ◽

pp. 1318-1323 ◽

Cited By ~ 69

Author(s):

FLORENCE BARON ◽

MICHEL GAUTIER ◽

GERARD BRULE

Keyword(s):

Salmonella Enteritidis ◽

Egg White ◽

Growth Potential ◽

Major Protein ◽

Inhibition Of Growth ◽

Cell Counts ◽

Inhibitory Factors ◽

Egg White Proteins ◽

White Resistance

This study was designed to investigate the growth potential of Salmonella enteritidis in liquid egg white at 30°C and to examine the mechanism of egg white resistance to Salmonella growth. We observed a low and variable growth in whole egg white: Salmonella cell counts rose by 2 log units during the 4 to 6 days of incubation. Treatments to render the egg white components more homogeneous and to facilitate the circulation of nutrients had no effect on the low and variable growth of Salmonella cells. To investigate whether a lack of nutrients or the presence of inhibitory factors could explain this low growth, the growth of various strains at 30°C in egg white filtrate (egg white without protein) was examined. Growth was fast and comparable with growth observed in optimum medium (tryptic soy broth). The addition of 10% egg white to the filtrate decreased the growth of Salmonella enteritidis to the same level observed in egg white, leading us to conclude that inhibitory factors, probably proteins, inhibit the growth of S. enteritidis. To determine the role of the different egg white proteins and to identify which of these inhibit S. enteritidis growth, the effect of each protein added to the filtrate was evaluated. To test the inhibitory potency of three binding proteins, supplementation with their corresponding ligands was also studied. Our study shows that ovotransferrin, or iron deficiency resulting from iron binding to ovotransferrin, was the major protein or mechanism implicated in the inhibition of the growth of S. enteritidis in egg white.

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Optimization of the Heating Conditions in the Production Process of High Gel Strength Egg White Powder

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.662.409 ◽

2013 ◽

Vol 662 ◽

pp. 409-412

Author(s):

Wei Xu ◽

Yu Jie Chi ◽

Yu Miao Hong

Keyword(s):

Production Process ◽

Egg White ◽

Heating Time ◽

Gel Strength ◽

White Powder ◽

Gel Properties ◽

Egg White Protein ◽

Egg White Powder ◽

Optimized Conditions ◽

Protein Production Process

In order to produce high gel strength egg white powder, Box-Behnken model was used to optimize the heating conditions in dry state of egg white protein production process. The gel properties of egg white powder were determined in various conditions. Results showed that the optimized conditions of heating conditions as follows: 84.8°C of temperature, 10.3 days of heating time, 10.3 % of relative humidity. Gel hardness of egg white powder increased from 408.36 g to 952.62 g through this treatment under the conditions. A tight and more uniform network with constant stability was observed in the gel of egg white powder after heating in SEM (5000×). The results showed that heating in dry state is an efficient method to improve gel properties of egg white powder.

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Effect of pH and Heat Treatment on the Antioxidant Activity of Egg White Protein-Derived Peptides after Simulated In-Vitro Gastrointestinal Digestion

Antioxidants ◽

10.3390/antiox9111114 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1114

Author(s):

Priyanka Singh Rao ◽

Emerson Nolasco ◽

Akihiro Handa ◽

Michael J. Naldrett ◽

Sophie Alvarez ◽

...

Keyword(s):

Heat Treatment ◽

Antioxidant Activity ◽

Protein Aggregation ◽

Critical Factor ◽

Protein Digestibility ◽

Egg White ◽

Egg White Protein ◽

Heat Treated ◽

Egg White Powder

The study aimed to analyze pH and heat treatment’s effect in modulating the release of peptides with antioxidant activity after simulated gastrointestinal (GI) digestion of Egg white powder (EWP). EWP samples with neutral (EWPN) and alkaline (EWPA) pH were heat-treated at 20, 60, and 90 °C and analyzed for protein aggregation, solubility, and GI digestibility. Heat treatment decreased solubility and induced protein aggregation, which was higher for EWPN as compared to EWPA. The unfolding of EWPA proteins at 60 °C exhibited a higher GI digestibility and antioxidant activity via Oxygen Radical Absorbance Capacity (ORAC) assay as compared to EWPN. Interestingly, a reverse trend was observed in the cellular antioxidant assay, and the GI-digest of EWPN exhibited a higher antioxidant activity. The LC-MS/MS analysis are in concordance with cellular antioxidant activity assay and showed a higher intensity for peptides with potential antioxidant activity in the GI-digest of EWPN. The results indicate that heat treatment but not the pH is a critical factor in improving the protein digestibility and releasing peptides with antioxidant activity after GI digestion.

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Role of Incubation Conditions and Protein Fraction on the Antimicrobial Activity of Egg White against Salmonella Enteritidis and Escherichia coli

Journal of Food Protection ◽

10.4315/0362-028x.jfp-10-157 ◽

2011 ◽

Vol 74 (1) ◽

pp. 24-31 ◽

Cited By ~ 17

Author(s):

MARIA ALABDEH ◽

VALÉRIE LECHEVALIER ◽

FRANÇOISE NAU ◽

MICHEL GAUTIER ◽

MARIE-FRANÇOISE COCHET ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Bacterial Growth ◽

Protein Concentration ◽

Salmonella Enteritidis ◽

Egg White ◽

Effect Of Temperature ◽

Egg White Protein ◽

Egg White Proteins

The mechanism of egg white antimicrobial activity involves specific molecules and environmental factors. However, it is difficult to compare the data from the literature because of the use of various bacterial strains and incubation conditions. The aim of our study was to determine the effect of temperature, pH, inoculum size, and egg white protein concentration on egg white antimicrobial activity and to investigate the putative interactions among these factors by conducting a complete factorial design analysis. The behavior of Salmonella Enteritidis and Escherichia coli was studied after precultivation in tryptic soy broth and Luria-Bertani broth, respectively, using three different egg white protein concentrations (0, 10, and 100%), five temperatures (37, 40, 42, 45, and 48°C), two pHs (7.8 and 9.3), and six inoculum levels (3 to 8 log CFU/ml). The essential role of temperature was identified. An inverse relationship was observed between bacterial growth and an increase in temperature. The role of egg white proteins was clearly demonstrated. In the absence of egg white proteins, bacterial growth occurred under most incubation conditions, whereas the presence of 10 and 100% protein produced bacteriostatic or bactericidal effects. The interaction between temperature and protein concentration was significant. At the highest tested temperatures, proteins were less involved in the bactericidal effect. Bacterial destruction was higher at pH 9.3 than at pH 7.8. Under our experimental conditions, Salmonella Enteritidis was more resistant to inactivation by egg white than was E. coli.

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High Intensity Pulsed Electric Fields Applied to Egg White: Effect on Salmonella Enteritidis Inactivation and Protein Denaturation

Journal of Food Protection ◽

10.4315/0362-028x-62.12.1381 ◽

1999 ◽

Vol 62 (12) ◽

pp. 1381-1386 ◽

Cited By ~ 77

Author(s):

ROMAIN JEANTET ◽

FLORENCE BARON ◽

FRANÇOISE NAU ◽

MICHEL ROIGNANT ◽

GÉRARD BRULÉ

Keyword(s):

Electric Field ◽

Electric Fields ◽

High Intensity ◽

Salmonella Enteritidis ◽

Protein Denaturation ◽

Egg White ◽

Pulse Number ◽

Dominant Factor ◽

Positive Interaction ◽

Positive Effects

High-intensity electric fields have been successfully applied to the destruction of Salmonella Enteritidis in diaultrafiltered egg white. The effects of electric field strength (from 20 to 35 kV·cm−1), pulse frequency (from 100 to 900 Hz), pulse number (from 2 to 8), temperature (from 4 to 30°C), pH (from 7 to 9), and inoculum size (from 103 to 107 CFU·ml−1) were tested through a multifactorial experimental design. Experimental results indicate that, for Salmonella inactivation, the electric field intensity is the dominant factor with a strongly positive effect, strengthened by its positive interaction with pulse number. Pulse number, temperature, and pH have also significant positive effects but to a lesser extent. In the most efficient conditions, the pulsed electric field (PEF) treatment is capable of 3.5 log10 reduction in viable salmonellae. Simultaneously, the measure of surface hydrophobicity does not indicate any increase after PEF treatment. These results suggest that no protein denaturation occurs, unlike what is observed after comparable heat treatment in terms of Salmonella inactivation (55°C for 15 min).

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Pengaruh Lama Pengasinan Terhadap Kadar Protein Putih Telur Itik

Journal of Health ◽

10.30590/vol1-no1-p36-39 ◽

2014 ◽

Vol 1 (1) ◽

pp. 36 ◽

Cited By ~ 1

Author(s):

Siti Fatimah ◽

Muji Rahayu ◽

Siti Aminah

Keyword(s):

Protein Level ◽

Egg White ◽

Special Treatment ◽

Egg White Protein ◽

Protein Levels ◽

Duck Egg ◽

Egg Period ◽

Graph Presentation ◽

And Control ◽

The Impact

Background : Egg is one of the animal protein source, which has delicious taste, easy to digest and highly nutritious. Besides its affordable price, its supply availability is unquestionable as well. However, due to its short storability, it requires special treatment, such as preserving, to store it for long period. One way to preserve the egg is by pickling egg, which generally requires seven to ten days of marinating. During the process of marinating, there will be a visual change of egg white and yolk. Their structures will be more solid (the occurrence of thickening process) because salinization will lead to protein denaturalization. Consequently, it has an influence as well towards the content of egg white protein of duck egg. This study is aimed to explore the impact of various time of pickling egg towards egg white protein of duck egg. Method : The study where takes place in a laboratories, is a true experimental study for the reason that the researcher must provide intervention, hence all of potentially confounding variables are manageable. Samples that had been used in this study are duck eggs which were bought from North Brebes. This study is expected to generate data from four various time of pickling egg and control (no treatment). Since there are four samples, accordingly the number of data resulted are twenty. The resulted data will be descriptively presented in table, graph, presentation, and narration. Result : Protein level examination within duck white egg shows changes in protein levels that occurs in every variation of pickling egg time, where the average results of the assay of duck egg white protein is 14.94% without treatment (control), in five days of pickling time is 13.68%, in seven days of pickling time is 13.29%, in nine days of pickling time is 12.87% and eleven days of pickling time is 12.78%. Conclusion : There is a significant impact among the period of pickling time to the protein level degradation of duck white egg. Keywords : Duck egg, period of pickling time, level protein of duck white egg.

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